I have looked for the CP99 model you describe with a 19 rd. PELLET magazine and can not find it. I see an 8 shot rotary clip and the 19 rd. BB magazine. I'd love to find one like you are describing. I, like the OP, am also searching for the most realistic, semi-auto air pistol. Ideally I'd like pellets but I don't like the idea of the rotary magazine and don't believe those types have a slide that locks open on the last round.This co2 pistol feels super good in your hands! its almost all metal except for the plastic grips. its heavy and feels like you're holding a reall P99. it has ambi mag release, mag holds nineteen pellets! (not BBs, but i've sent many racoons flying with this thing). The fully metal slide blows back after every shot which kicks like a 22 pistol and also recocks the striker, so you have an extremely light SA trigger every time. just rack the slide before the first shot and you're good! oh yeah and the slide locks back after the last shot, flick the slide release and the metal slide clanks shut, trust me, you WILL feel retty hardcore with this thing . its got sights that are molded into the slide, so theyre not adjustable, but its ok cuz its pretty stinkin accurate. just expect to go through a little more co2 cuz of the blowback, but its really not that much.
out of all the bb guns ive handled, this one is as close to realistic as it gets: http://www.umarexusa.com/detail.aspx?ID=120
I recently borrowed a friends Walther PPK BB pistol and was very impressed by the authenticity of the weapon. I have been using it to teach my six year old daughter how to handle a pistol and it's size and realism are excellent for that purpose. I decided I'd like to get one similar but preferred a pellet pistol with a bottom loading magazine, functioning slide, single and double action and the slide locking open after the last round.
Sorry if I'm dragging up an old thread here but I found it on google search when researching this topic.